High defibrillation threshold in patients with implantable cardioverter-defibrillator. How to solve the problem, single-center experience

Abstract

Standard implantable cardioverter-defibrillator with transvenous leads systems have proven to be effective in terminating ventricular tachyarrhythmias in most patients (more then 90%) with sufficient safety margin, i.e. difference between maximal output energy of the ICD and defibrillation threshold. However in some clinical situation it is not possible, energy requirement is higher than normal, it is called high defibrillation threshold. We report clinical data of 3 patients with high defibrillation threshold among 415 ICD’s implanted in our institution (cases of ischaemic cardiomyopathy, dilated cardiomyopathy and hypertrophic cardiomyopathy are presented). We summarize our experience, therapeutic options and literature review investigating factors which influence defibrillation threshold: related to underlying cardiac disease, therapy (drugs interactions) and ICD system( lead and pulse generator type).